public HinhTron(DiemOxy a, double c)
{
this.i = new DiemOxy(a);
this.R = c;
}
public HinhTron(HinhTron a)
{
this.i = a.i;
this.R = a.R;
}
public HinhTron()
{
this.i = new DiemOxy();
this.R = 0;
}